Copper alloy



Patented Apr. 22, 1941 Franz B. Reuse! and Earl I. Larsen, Indianapolis,

to 1'. B. Mallory & 00., Inc.,

Ind anlgnors Indianapolis, Ind.,

a corporation of Delaware No Drawing. Application December 4, 1940, Serial No. 368,443

4 Claims. (Cl. 75-153) This invention relates to alloys and more particularly to copper alloys of improved characteristics.

An object of the invention is to produce an improved copper base alloy.

Another object is to produce a copper-tellurium alloy which is highly susceptible to age hardening and work hardening.

Another object is to provide an alloy of high hardness, coupled with high electrical and thermal characteristics.

Other objects'of the invention will be apparent from the following description taken in connection with the appended claims.

The present invention comprises the combination of elements, methods of manufacture and the product thereof, brought out and exemplified in the disclosure hereinafter set forth, the scope of the invention being indicated in the appended claims.

while a preferred embodiment of the invention is described herein, it is contemplated that considerable variation may be made in the method of procedure and the combination of elements without departing from the spirit of the invention.

The invention relates to alloys of copper, tellurium and chromium. While these alloys may vary in their physical characteristics with the type of treatment received and the proportions of various ingredients, they will generally be characterized by high conductivity and hardness and by heat resistance.

According to the preferred method of carrying out our present invention, an alloy is made in substantially the following proportions:

Per cent. Tellurium .1-3 Chrnminm .1-

Copper-balance.

. Per cent Chromium .li-lyi Tellurium .1-1

In case of the alloys prepared by means of powder metallurgy, the ingredients are thoroughly mixed together, pressed and sintered at suitwelding purposes.

able temperatures. It is possible to rc-press and re-sinter if necessary, to obtain a very high density.

After the alloys have been prepared, according to the methods described :a ve, the heat treatment may be carried out by raising the temperature to above 100 deg. 0.. and preferably to a temperature in the order of 800-1000 deg. C. The alloy is then quenched from this high temperature and subsequently aged at a temperature below 100 deg. C. and preferably in the range between 400-600 deg. C. This heat treatment results in considerable improvement in the powders, difiusion of the chromium into the copper, takes place, and that the molded product is susceptible to'heat treatment in very much the same manner as the diffused alloy.

We have been able to obtain, with the present composition in a molded product, an electrical and thermal conductivity, that of pure copper. The hardness after heat treatment may vary from 50-75 Rockwell B and can be still further increased by cold working.

The alloys made in accordance with the present' invention were tested for a number of applications. It was found that the new and improved alloys are superior as electrical contacting members. Tests were conducted on a single coil magnetic contactor at a voltage of 230 volts, breaking a current of amps. at a power factor of 32%. It was found that the new and improved alloy would retain a low contact resistance and would have a low weight loss.

Tests were also conducted with this material for spot welding and more generally resistance The material resisted mushrooming extremely well and could be used for a large number of resistance welding applications. The material had some self-dressing characteristics which must be attributed to the presence of tellurium. The material also would not stick as readily as other materials of a similar composition, but not containing tellurium.

Excellent results were obtained with the material when used as welding tips for gas welding torches and gas cutting torches. The tips made of our new alloy will not soften, and will resist oxidation to a very considerable degree. Welding tips of this type contain usually a number of very small holesand it was found that the present material lends itself very readily to the accurate fabrication of such small diameter holes. Very often also these welding tips have'to withstand wear and abuse. The hardness of this new alloy increases the life of these welding tips many times over that of other materials used heretofore. Up to the present time some of these tips were constructed in such a way that threaded steel nuts were attached to the tip for fastening it into the welding torch body. With the hardness obtainable in the alloy of the present invention, these steel nuts can be eliminated and the manufacture oi the tips thereby made more economical.

While the Present invention as to its objects and advantages has been described herein as carried out in specific embodiments thereof, it is not desired to be limited thereby, but it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed is:

1. An alloy containing .1 to 3% tellurium, .1 to 10% chromium, balance copper.

2. An age hardened alloy composed of about .1 to 3% tellurium, .1 to 10% chromium, balance substantially all copper, characterized by a combination of high hardness and high electrical and thermal conductivity.

3. An alloy of high strength, high hardness and high electrical and thermal conductivity, consisting of tellurium and chromium, each .20 to 1% by weight, and the balance copper, the alloy being substantially free oi! other alloying constituents.

4. A welding or cutting tip for gas welding, composed 01' an alloy containing .1 to 3% tellurium, .1 to 10% chromium, balance copper.

FRANZ R. HENSEL. EARL I. LARSEN. 

